Another Wiseco Ring Gap
 

Hiya, browsed through the threads related to Wiseco ring gaps and unfortunately I havent found an answer to my problem. Dont flame too hard for the question ;P

Bought a set of Wiseco 83.5mm NPR XX rings and all of the 2nd rings are larger out of the box than specified by Wiseco's sheet (bore * 0.0055 which would be 0.018") at 0.023" - 0.024"
I also have a top ring that was opened up to 0.022" which is larger than the 0.01643" which I was going to round up to 0.017".

Are either or both of these a problem? If the top ring is an issue no big deal as its easy enough to buy a new set but Im a little more concerned that all 2nd rings are considerably over the minimums from Wiseco

What pistons are you using and what is the piston to wall clearance?

Generally, the ring gap you're seeing for the 2nd rings (0.023"-0.024") is a bit larger than the spec but still within a reasonable range. The larger gap can help with higher performance or tolerance for heat expansion, especially in boosted or high-performance engines. As for the top ring being at 0.022", it's a bit over the spec, but it's still not a huge deal unless you’re building a very specific setup.

I ended up buying another set of rings for the one that is 0.022" and will keep them at 0.017-0.018". Ill run the factory gap for the second rings

Im running Supertech 83.5mm 8.8:1 which was recommended by Fab9. Cylinders were bored 0.02" over to accommodate. Im unsure on piston-to-wall clearance but included with the pistons from Fab9 were 83.5mm piston rings from wiseco

If the ptw is relatively large the rings will have a large end gap out of the box. I prefer to run an extra .001” ptw over the FI spec with the ST pistons. A .001” increase in bore dia equals .003” in end gap.

The end gap will increase about .003-.004” with some use. .020 for the top is ok, anything under .018” is too tight for higher boost. The second ring doesn’t really matter, it’s just a scraper.

Aways remember with ring gaps gap at highest boost & temperature planned then add a bit.
To big even by a lot is safe. To small, even by a little is disastrous.

I recently put in a set of Wiseco pistons and rings in my NB2 block, bored to 84 mm.
I don't remember the gap numbers. What I do remember is I looked at the numbers on the sheet that came with it, thought they seemed a bit off, and called Wisco for technical support.
The guy I spoke to said the sheet is but a guideline. He then looked up specific recommendations for my application, road racing, with 8 psi boost, and gave me some numbers.
First ring gap was a bit larger than the sheet, second was a bit smaller.
Just call them, they made them.

The rings are made by NPR.

Either way, just call them. Mine did come in the box with the Wiseco pistons, supplied by Wiseco, so they seemed like the folks to ask